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Full text of "Treatise On Applied Analytical Chemistry(Vol-1)"

434

BEESWAX

BEESWAX

Crude, (virgin} wax in pale yellow or brown. European qualities are
yellow or pale yellow, the African and American reddish-yellow to brown,
and the Indian greyish-brown. It is fatty to the touch and soft and plastic
to the heat of the hand, and presents a granular fracture. It has a special
odour, recalling that of honey, and a faintly balsamic taste.

White or bleached wax (decolorised by air and light or by chemical means)
is white, brittle, and only slightly fatty and odoriferous.

In general the wax is almost insoluble in cold alcohol but partly soluble
in boiling absolute alcohol, from which it separates on cooling. It is slightly
soluble in cold ether, more so in boiling ether, chloroform or benzene.

It consists principally of cerotic acid and myricyl palmitate (myricin),
but contains also free melissic acid and ceryl alcohol and hydrocarbons
(3-12%, according to the origin).

The physical and chemical characters of different types of beeswax are
given in Table XLIX.

The wax may be adulterated with stearine, colophony, paraffin wax
or ceresine, Chinese (insect) wax, carnauba wax, Japan wax (so-called),
tallow, wool fat, flour or starch, and mineral substances ; water may also
be present. The colour may be enhanced by turmeric or coal-tar colours.

Imitations of the wax are made with paraffin wax, ceresine and colophony,
or with various mixtures of paraffin wax, carnauba wax, Japan wax, stearine,
etc., often coloured with coal-tar colours.

To detect the different adulterations and imitations here indicated, it
is necessary to determine the various characters (see 1-5) and further to
apply certain special tests (see 6-13), since it is possible to prepare mixtures
with the characters of the pure wax. If, on the other hand, the detection
of beeswax in mixtures with other substances is required, test 14 is employed.

In the case of the crude (virgin) wax, before proceeding to the analysis
(with the exception of the determinations 12), it is well to boil the sample
with water to remove the whole of the honey and then to filter the fused
mass in the hot.

1.  Specific Gravity.—This may be determined most exactly by means
of the specific gravity bottle, but Hager's method may also be used.   The
wax is melted at a gentle heat and poured in drops into cold 70% alcohol,
the beads of wax thus obtained being dried in absorbent paper, left over-
night to solidify and then immersed in alcohol of known specific gravity,
e.g., 0-965, at 15°.   If the beads remain suspended at any point of the
liquid, the specific gravity of the wax is that of the liquid, i.e., 0-965 ; if,
on the other hand, they sink or float, tests are made with more dilute or
more concentrated alcohols until the correct specific gravity is obtained.
It is usually sufficient to prepare eight or ten alcohol solutions with specific
gravities from 0-960 upwards.

It is also desirable to determine the specific gravity of the wax at 98-100°
(see General Methods, 3).

2.  Melting Point.—As in General Methods, 4.

3.  Acid and Saponification Numbers.—These may be determinedtelleri)      .     .     . Porpoise,  from   the  body   (Del-phinus phocaena)